A. Field of the Invention
The present invention relates to safety apparatus for protecting against injurious or potentially fatal falls of workers such as construction workers or window washers working at elevations of more than a few feet above the ground. More particularly, the invention relates to a personal fall arrestment apparatus which includes a self-retracting lanyard (SRL) and a remotely operable attachment device for the SRL that enables the anchoring connector ring of the SRL to be remotely attachable by a workman to fixed anchor members located at elevations above the reach of a workman.
B. Description of Background Art
Federal and state safety regulations such as those promulgated by OSHA or Cal/OSHA routinely include requirements that persons exposed to fall hazards during the course of their work be protected from injury or death by a personal fall arrest system. Such systems typically include a body harness which is secured around the body of a worker and hooked to a self-retracting lanyard (SRL). The SRL includes a housing that has an upper attachment connector ring which is securable to a fixed anchoring member such as a J-bar or eye-bolt located above a working level and securely fastened to an anchoring structure such as a beam or column of a building.
The SRL of a typical personal fall arrestment system includes a lifeline consisting of a cable or belt which retractably extends from a lower part of the SRL housing, and has at the lower end thereof a swivel connector which is releasably fastenable to a body harness. A typical SRL contains within its housing a shock absorbing deceleration device which allows a pre-determined length of lifeline to pay out from the housing in response to tension exerted on the lifeline caused by movement of a worker away from an anchoring member. Typically, the deceleration device includes a spool or reel which allows a pre-determined length of about two to six feet of lifeline to pay out from the SRL housing with little resistance, thus enabling the worker to move horizontally on scaffolding, or to free-fall that distance.
An SRL deceleration device also includes a mechanism such as a spiral clock spring, which exerts an increasing torque on the spool or reel to thus gradually decrease the rate at which a safety line or web may be paid out from the SRL housing, thus decelerating the falling worker to a complete stop over a distance of, for example, about 3.5 feet. The total maximum length of safety line which may be withdrawn from a typical SRL deceleration device, e.g., from about 5.5 feet to about 9.5 feet, is chosen to have a value sufficient to position the feet of a workman above the ground or any obstruction such as a protruding part of a building or scaffolding below him, thus preventing the workman from impact injury.
Personal fall arrestment systems of the type described above are widely used and effective. However, there is a problem associated with the use of such systems in many practically encountered situations, as will now be described.
The self-retracting lanyard (SRL) or other such deceleration device of a fall arrest system must be quickly and easily but securely attachable to and removable from a fixed anchoring member at a work site, at a location above a worker. A releasable SRL anchoring support connector ring used for this purpose must not only be easily attachable to and removable from an anchoring member, but must also be capable of withstanding large tensional dynamic loads, such as those imposed by a 200-lb man falling and pulling on the lifeline connected to the deceleration device. Because of the large potential dynamic loads which a self-retracting lanyard (SRL) connector ring must withstand, such connector rings are typically constructed to be capable of withstanding static loads of up to 3000 lbs.
Since anchoring connector rings of self-retracting lanyards and other such deceleration devices must be readily attachable to an anchoring member such as an eye-bolt which has a closed ring shape, SRL anchoring connectors are typically of the carabiner type. Carabiner connectors have the form of an oval or D-shaped ring which has a locking link or gate pivotable from a locked position to an open position in which the D-shaped ring is closed. In the open and unlocked position, an upper end of the gate link which was locked to the lower end of a downwardly curved, hook-like upper front segment of the D-shaped ring may be pivoted away from the upper front segment of the D-shaped ring. This position enables the now unobstructed lower end of the upper front segment to be inserted into a closed ring of an anchoring member, such as the eye of an eye-bolt, or hooked around a rebar. The locking gate link must also be pivotable back to a locked position after the carabiner connector ring has been connected to an anchoring member.
Most safety standards require that two distinct actions be performed to unlock and open the locking gate link of an anchoring connector ring such as the carabiner type connector ring described above. For example, a carabiner connector widely used in existing fall arrestment systems requires the following two distinct actions to open the locking gate link. First, a cylindrical sleeve of the locking gate link must be twisted about its longitudinal axis to disengage a locking lug at the upper end of the locking gate link from a slot in the lower end of the downwardly curved upper end segment of the connector ring. Second, the twisted locking gate sleeve is pulled away from the downwardly curved upper end of the carabiner connector ring. The twisted and tensioned locking gate link is then pivoted towards the interior of the carabiner connector ring to create an opening between the lower end of the downwardly curved upper front segment of the connector ring, which may then be inserted into the eye of an eye-bolt, hooked around a rebar, or attached to another such anchoring member. The carabiner connector ring is then securely locked to the anchoring member by reversing the foregoing steps. These steps consist of releasing tension and torque on the twisted locking gate sleeve. Spring tension provided by spring components of the locking gate then cause the twisted locking gate sleeve to lockingly re-engage the downwardly protruding upper end of the carabiner connector ring.
Since SRL anchoring connectors including carabiner type connector rings of the type described above must be secured to an anchoring member which is usually several feet or more above the head of a worker, it can be readily appreciated that securing an SRL anchoring connector ring to an elevated anchoring member at a work site may be problematic. The present invention was developed to solve such problems by providing a personal fall arrestment apparatus that includes an attachment device which enables the connector ring at the upper end of an SRL to be remotely attachable to and removable by a workman to an anchoring member located above and beyond the convenient reach of the workman.